Open AccessDiversity of freshwater molluscs from the upper Brahmaputra Basin, Assam, India
Author(s) -
Jyotirmoy Sonowal,
Munmi Puzari,
Devid Kardong
Publication year - 2021
Publication title -
journal of threatened taxa
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.264
H-Index - 8
eISSN - 0974-7907
pISSN - 0974-7893
DOI - 10.11609/jott.7144.13.5.18237-18246
Subject(s) - tributary , iucn red list , structural basin , species richness , ecology , threatened species , geography , data deficient , drainage basin , bivalvia , biology , fishery , mollusca , habitat , paleontology , cartography
A field survey was conducted for three consecutive years, 2015–17 to assess the diversity of freshwater molluscs (Gastropoda and Bivalvia) of the upper Brahmaputra Basin in Assam, India. Altogether, 18 gastropods and 27 bivalve species representing nine families were recorded from 17 sampling stations comprising small to large tributaries and wetlands in the flood-plains covering a total geographical area of approximately 3,500km2. A large fraction (15.55%) of the collected mollusc species are new records from the upper Brahmaputra Basin of Assam. Rarity in the occurrence of freshwater mollusc was confirmed with singleton and doubleton species accounting for 6.66% and unique species accounting for 35.55% of the total species recorded. It was observed that most of the mollusc species of the upper Brahmaputra Basin are either in the ‘Least Concern’ or ‘Data Deficient’ category of the IUCN Red List; except for Lymnaea ovalior (Annandale & Prashad, 1921) and Sphaerium austeni Prashad, 1921 assessed as ‘Vulnerable’ and ‘Near Threatened’, respectively. A significant trend in the diversity in terms of species richness and composition was observed across the sampling stations of the northern basin and southern basin of the river Brahmaputra.